OSG Extension Tap: 1/2"-13 UNC, H3 / 2B-3B, 3 Flute, Plug Chamfer
The OSG Extension Tap (MPN 1295501) is a 1/2"-13 UNC spiral-point extension tap with a plug chamfer, made from black oxide high-speed steel. It features 3 flutes and is rated H3 / 2B-3B for thread class tolerance.
SKU 3G-OTH-313646
Need installation or engineering help?
Ask a question
Product Description
The OSG Extension Tap (MPN 1295501) is a 1/2"-13 UNC spiral-point extension tap with a plug chamfer, made from black oxide high-speed steel. It features 3 flutes and is rated H3 / 2B-3B for thread class tolerance.
Frequently Asked Questions
What is an OSG extension tap used for?
An OSG extension tap is used to cut internal threads in deep or hard-to-reach holes. The extended shank allows access where standard taps cannot reach, making it ideal for machining, automotive, and general manufacturing applications.
What are the specifications of the OSG extension tap 1295501?
The OSG extension tap 1295501 is a 1/2"-13 UNC spiral-point tap with a plug chamfer, 3 flutes, and black oxide high-speed steel construction. It has an H3 / 2B-3B tolerance class, suitable for threading through holes in steel and other materials.
Where to buy OSG extension taps worldwide?
3G Electric supplies OSG extension taps worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for pricing and lead time on the OSG 1295501 or other industrial tooling needs.
How to select the right OSG extension tap for deep hole threading?
Select an OSG extension tap based on thread size, material, and hole depth. For through holes, a spiral-point plug chamfer tap like the 1295501 pushes chips ahead. Match the H3 / 2B-3B tolerance to your required thread class and use proper cutting fluid.
Used in
Common applications for OSGOSG Products
3G Electric supplies OSG spiral-point extension taps. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.















